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Ji W, Zheng B, Zhang A. Research progress of the relationship between phosphoprotein phosphatases (PPPs) and neurodevelopmental disorders. Clin Genet 2024. [PMID: 39300798 DOI: 10.1111/cge.14617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 08/29/2024] [Accepted: 09/01/2024] [Indexed: 09/22/2024]
Abstract
Reversible protein phosphorylation is a ubiquitous phenomenon essential for eukaryotic cellular processes. Recent advancements in research about neurodevelopmental disorders have prompted investigations into the intricate relationship between protein phosphatases, particularly phosphoprotein phosphatases (PPPs), and neurodevelopment. Notably, variants in 10 coding genes spanning four PPP family members have been implicated in neurodevelopmental disorders. Here, we provide a comprehensive overview of the clinical phenotypes, genotypes, and pathogenic mechanisms observed in affected patients. Our analysis reveals challenges in subsequent statistical analyses due to inconsistent clinical phenotypic descriptions and a lack of large multicenter studies, hampering analysis about genotype-phenotype correlations. The scarcity of follow-up data poses a significant obstacle to prognostic counseling for nearly all rare diseases. Presently, symptomatic treatment strategies are employed for patients with variants, as definitive cures remain elusive. Future research may explore protein phosphatase regulators as potential therapeutic targets. Furthermore, it is imperative not to overlook other members of the protein phosphatase family or coding genes with undiscovered variants. Insights gleaned from the temporal and spatial distribution of proteins, along with observations from animal model phenotypes, may provide valuable directions for uncovering novel pathogenic genes.
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Affiliation(s)
- Wenya Ji
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Bixia Zheng
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Aihua Zhang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China
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2
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Ganga AK, Sweeney LK, Rubio Ramos A, Wrinn CM, Bishop CS, Hamel V, Guichard P, Breslow DK. A disease-associated PPP2R3C-MAP3K1 phospho-regulatory module controls centrosome function. Curr Biol 2024:S0960-9822(24)01172-2. [PMID: 39317195 DOI: 10.1016/j.cub.2024.08.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 08/08/2024] [Accepted: 08/30/2024] [Indexed: 09/26/2024]
Abstract
Centrosomes have critical roles in microtubule organization, ciliogenesis, and cell signaling.1,2,3,4,5,6,7,8 Centrosomal alterations also contribute to diseases, including microcephaly, cancer, and ciliopathies.9,10,11,12,13 To date, over 150 centrosomal proteins have been identified, including several kinases and phosphatases that control centrosome biogenesis, function, and maintenance.2,3,4,5,14,15,16,17,18,19,20,21 However, the regulatory mechanisms that govern centrosome function are not fully defined, and thus how defects in centrosomal regulation contribute to disease is incompletely understood. Using a systems genetics approach, we find here that PPP2R3C, a poorly characterized PP2A phosphatase subunit, is a distal centriole protein and functional partner of centriolar proteins CEP350 and FOP. We further show that a key function of PPP2R3C is to counteract the kinase activity of MAP3K1. In support of this model, MAP3K1 knockout suppresses growth defects caused by PPP2R3C inactivation, and MAP3K1 and PPP2R3C have opposing effects on basal and microtubule stress-induced JNK signaling. Illustrating the importance of balanced MAP3K1 and PPP2R3C activities, acute overexpression of MAP3K1 severely inhibits centrosome function and triggers rapid centriole disintegration. Additionally, inactivating PPP2R3C mutations and activating MAP3K1 mutations both cause congenital syndromes characterized by gonadal dysgenesis.22,23,24,25,26,27,28 As a syndromic PPP2R3C variant is defective in centriolar localization and binding to centriolar protein FOP, we propose that imbalanced activity of this centrosomal kinase-phosphatase pair is the shared cause of these disorders. Thus, our findings reveal a new centrosomal phospho-regulatory module, shed light on disorders of gonadal development, and illustrate the power of systems genetics to identify previously unrecognized gene functions.
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Affiliation(s)
- Anil Kumar Ganga
- Department of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Avenue, New Haven, CT 06511, USA
| | - Lauren K Sweeney
- Department of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Avenue, New Haven, CT 06511, USA
| | - Armando Rubio Ramos
- Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva, Switzerland
| | - Caitlin M Wrinn
- Department of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Avenue, New Haven, CT 06511, USA
| | - Cassandra S Bishop
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva, Switzerland
| | - Paul Guichard
- Department of Molecular and Cellular Biology, Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva, Switzerland
| | - David K Breslow
- Department of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Avenue, New Haven, CT 06511, USA.
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Musumeci A, Vinci M, Verbinnen I, Treccarichi S, Nigliato E, Chiavetta V, Greco D, Vitello GA, Federico C, Janssens V, Saccone S, Calì F. PPP2R5E: New gene potentially involved in specific learning disorders and myopathy. Gene 2024; 933:148945. [PMID: 39284558 DOI: 10.1016/j.gene.2024.148945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 09/05/2024] [Accepted: 09/11/2024] [Indexed: 09/21/2024]
Abstract
Protein phosphatase 2A (PP2A) is a family of multifunctional enzymatic complexes crucial for cellular signalling, playing a pivotal role in brain function and development. Mutations in specific genes encoding PP2A complexes have been associated with neurodevelopmental disorders with hypotonia and high risk of seizures. In the current work, we present an individual with specific learning problems, motor coordination disorders, hypotonia and behavioural issues. Although whole exome sequencing (WES) did not unveil pathogenic variants in known genes related to these symptoms, a de novo heterozygous variant Glu191Lys was identified within PPP2R5E, encoding the PP2A regulatory subunit B56ε. The novel variant was not observed in the four healthy brothers and was not detected as parental somatic mosaicism. The mutation predicted a change of charge of the mutated amino acid within a conserved LFDSEDPRER motif common to all PPP2R5 B-subunits. Biochemical assays demonstrated a decreased interaction with the PP2A A and C subunits, leading to disturbances in holoenzyme formation, and thus likely, function. For the first time, we report a potential causal link between the observed variant within the PPP2R5E gene and the symptoms manifested in the subject, spanning specific learning problems and motor coordination disorders potentially associated with myopathy.
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Affiliation(s)
- Antonino Musumeci
- Oasi Research Institute-IRCCS, via Conte Ruggero 73, 94018, Troina, EN, Italy
| | - Mirella Vinci
- Oasi Research Institute-IRCCS, via Conte Ruggero 73, 94018, Troina, EN, Italy
| | - Iris Verbinnen
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), Herestraat 49, PO-box 901, B-3000 Leuven, Belgium
| | - Simone Treccarichi
- Oasi Research Institute-IRCCS, via Conte Ruggero 73, 94018, Troina, EN, Italy
| | - Eleonora Nigliato
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), Herestraat 49, PO-box 901, B-3000 Leuven, Belgium
| | - Valeria Chiavetta
- Oasi Research Institute-IRCCS, via Conte Ruggero 73, 94018, Troina, EN, Italy
| | - Donatella Greco
- Oasi Research Institute-IRCCS, via Conte Ruggero 73, 94018, Troina, EN, Italy
| | | | - Concetta Federico
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via Androne 81, 95124 Catania, Italy
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), Herestraat 49, PO-box 901, B-3000 Leuven, Belgium
| | - Salvatore Saccone
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via Androne 81, 95124 Catania, Italy.
| | - Francesco Calì
- Oasi Research Institute-IRCCS, via Conte Ruggero 73, 94018, Troina, EN, Italy
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Seneff S, Kyriakopoulos AM, Nigh G. Is autism a PIN1 deficiency syndrome? A proposed etiological role for glyphosate. J Neurochem 2024; 168:2124-2146. [PMID: 38808598 DOI: 10.1111/jnc.16140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/30/2024]
Abstract
Autism is a neurodevelopmental disorder, the prevalence of which has increased dramatically in the United States over the past two decades. It is characterized by stereotyped behaviors and impairments in social interaction and communication. In this paper, we present evidence that autism can be viewed as a PIN1 deficiency syndrome. Peptidyl-prolyl cis/trans isomerase, NIMA-Interacting 1 (PIN1) is a peptidyl-prolyl cis/trans isomerase, and it has widespread influences in biological organisms. Broadly speaking, PIN1 deficiency is linked to many neurodegenerative diseases, whereas PIN1 over-expression is linked to cancer. Death-associated protein kinase 1 (DAPK1) strongly inhibits PIN1, and the hormone melatonin inhibits DAPK1. Melatonin deficiency is strongly linked to autism. It has recently been shown that glyphosate exposure to rats inhibits melatonin synthesis as a result of increased glutamate release from glial cells and increased expression of metabotropic glutamate receptors. Glyphosate's inhibition of melatonin leads to a reduction in PIN1 availability in neurons. In this paper, we show that PIN1 deficiency can explain many of the unique morphological features of autism, including increased dendritic spine density, missing or thin corpus callosum, and reduced bone density. We show how PIN1 deficiency disrupts the functioning of powerful high-level signaling molecules, such as nuclear factor erythroid 2-related factor 2 (NRF2) and p53. Dysregulation of both of these proteins has been linked to autism. Severe depletion of glutathione in the brain resulting from chronic exposure to oxidative stressors and extracellular glutamate leads to oxidation of the cysteine residue in PIN1, inactivating the protein and further contributing to PIN1 deficiency. Impaired autophagy leads to increased sensitivity of neurons to ferroptosis. It is imperative that further research be conducted to experimentally validate whether the mechanisms described here take place in response to chronic glyphosate exposure and whether this ultimately leads to autism.
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Affiliation(s)
- Stephanie Seneff
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | | | - Greg Nigh
- Immersion Health, Portland, Oregon, USA
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DeMarco AG, Dibble MG, Hall MC. Inducible degradation-coupled phosphoproteomics identifies PP2A Rts1 as a novel eisosome regulator. Front Cell Dev Biol 2024; 12:1451027. [PMID: 39234563 PMCID: PMC11371571 DOI: 10.3389/fcell.2024.1451027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Accepted: 08/02/2024] [Indexed: 09/06/2024] Open
Abstract
Introduction Reversible protein phosphorylation is an abundant post-translational modification dynamically regulated by opposing kinases and phosphatases. Protein phosphorylation has been extensively studied in cell division, where waves of cyclin-dependent kinase activity, peaking in mitosis, drive the sequential stages of the cell cycle. Here we developed and employed a strategy to specifically probe kinase or phosphatase substrates at desired times or experimental conditions in the model organism Saccharomyces cerevisiae. Methods We combined auxin-inducible degradation (AID) with mass spectrometry-based phosphoproteomics, which allowed us to arrest physiologically normal cultures in mitosis prior to rapid phosphatase degradation and phosphoproteome analysis. Results and discussion Our results revealed that protein phosphatase 2A coupled with its B56 regulatory subunit, Rts1 (PP2ARts1), is involved in dephosphorylation of numerous proteins in mitosis, highlighting the need for phosphatases to selectively maintain certain proteins in a hypophosphorylated state in the face of high mitotic kinase activity. Unexpectedly, we observed elevated phosphorylation at many sites on several subunits of the fungal eisosome complex following rapid Rts1 degradation. Eisosomes are dynamic polymeric assemblies that create furrows in the plasma membrane important in regulating nutrient import, lipid metabolism, and stress responses, among other things. We found that PP2ARts1-mediated dephosphorylation of eisosomes promotes their plasma membrane association and we provide evidence that this regulation impacts eisosome roles in metabolic homeostasis. The combination of rapid, inducible protein degradation with proteomic profiling offers several advantages over common protein disruption methods for characterizing substrates of regulatory enzymes involved in dynamic biological processes.
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Affiliation(s)
- Andrew G DeMarco
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Marcella G Dibble
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Mark C Hall
- Department of Biochemistry, Purdue University, West Lafayette, IN, United States
- Institute for Cancer Research, Purdue University, West Lafayette, IN, United States
- Institute for Drug Discovery, Purdue University, West Lafayette, IN, United States
- Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, United States
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Brewer A, Zhao JF, Fasimoye R, Shpiro N, Macartney TJ, Wood NT, Wightman M, Alessi DR, Sapkota GP. Targeted dephosphorylation of SMAD3 as an approach to impede TGF-β signaling. iScience 2024; 27:110423. [PMID: 39104417 PMCID: PMC11298613 DOI: 10.1016/j.isci.2024.110423] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 05/09/2024] [Accepted: 06/27/2024] [Indexed: 08/07/2024] Open
Abstract
TGF-β (transforming growth factor-β) signaling is involved in a myriad of cellular processes and its dysregulation has been implicated in many human diseases, including fibrosis and cancer. TGF-β transcriptional responses are controlled by tail phosphorylation of transcription factors SMAD2 and SMAD3 (mothers against decapentaplegic homolog 2/3). Therefore, targeted dephosphorylation of phospho-SMAD3 could provide an innovative mechanism to block some TGF-β-induced transcriptional responses, such as the transcription of SERPINE-1, which encodes plasminogen activator inhibitor 1 (PAI-1). Here, by developing and employing a bifunctional molecule, BDPIC (bromoTAG-dTAG proximity-inducing chimera), we redirected multiple phosphatases, tagged with bromoTAG, to dephosphorylate phospho-SMAD3, tagged with dTAG. Using CRISPR-Cas9 technology, we generated homozygous double knock-in A549 bromoTAG/bromoTAG PPM1H/ dTAG/dTAG SMAD3 cells, in which the BDPIC-induced proximity between bromoTAG-PPM1H and dTAG-SMAD3 led to a robust dephosphorylation of dTAG-SMAD3 and a significant decrease in SERPINE-1 transcription. Our work demonstrates targeted dephosphorylation of phospho-proteins as an exciting modality for rewiring cell signaling.
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Affiliation(s)
- Abigail Brewer
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Jin-Feng Zhao
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Rotimi Fasimoye
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Natalia Shpiro
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Thomas J. Macartney
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Nicola T. Wood
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Melanie Wightman
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Dario R. Alessi
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gopal P. Sapkota
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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Bartol TM, Ordyan M, Sejnowski TJ, Rangamani P, Kennedy MB. A spatial model of autophosphorylation of Ca 2+ /calmodulin-dependent protein kinase II in a glutamatergic spine reveals dynamics of kinase activation in the first several seconds after a complex synaptic stimulus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.02.578696. [PMID: 38352446 PMCID: PMC10862815 DOI: 10.1101/2024.02.02.578696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Long-term potentiation (LTP) is a biochemical process in excitatory glutamatergic synapses in the Central Nervous System (CNS). It is initiated by a bout of synaptic activation that is strong enough to contribute to production of an action potential in the axon of the postsynaptic neuron, and it results in an increase in the size of postsynaptic depolarization during subsequent activity. The first step leading to LTP is activation and autophosphorylation of an abundant postsynaptic enzyme, Ca 2+ /calmodulin-dependent protein kinase II (CaMKII). We use simulation of activation of CaMKII holoenzymes in a realistic spatial model of a spine synapse, created in MCell4, to test three hypotheses about how the autophosphorylation response of CaMKII is shaped during a repeated high-frequency stimulus. First, the simulation results indicate that autophosphorylation of CaMKII does not constitute a bistable switch under biologically realistic conditions. Instead, prolonged autophosphorylation of CaMKII may contribute to a biochemical "kinetic proof-reading" mechanism that controls induction of synaptic plasticity. Second, concentration of CaMKII near the postsynaptic membrane increases the local concentration of kinase activity. However, neither localization nor "Ca 2+ -calmodulin-trapping (CaM-trapping)" increase the proportion of autophosphorylated subunits in holoenzymes after a complex stimulus, as previously hypothesized. Finally, we show that, as hypothesized, the amplitude of autophosphorylation in the first 30 seconds after a stimulus is extremely sensitive to the level and location of PP1 activity when PP1 is present in biologically accurate amounts. We further show that prolonged steric hindrance of dephosphorylation of CaMKII, caused by CaM-trapping, can increase the amplitude of autophosphorylation after a complex stimulus. These simulation results sharpen our quantitative understanding of the early events leading to LTP at excitatory synapses. Author Summary Neurons in the brain are interconnected in an organized fashion by synapses that transmit neuronal activity from one neuron to another. Most of the billions of neurons in the brain have about 10,000 synapses spread over the neuronal membrane. Information is stored in the brain when the ability of specific synapses to pass along neuronal activity is strengthened resulting in formation of new networks. The increase in strength of a synapse is tightly controlled by the frequency and amplitude of its activity, and by neurohormonal signals, which, in combination, can cause long-lasting biochemical changes at the synapse that underlie learning and memory. Defects in these biochemical pathways cause mental and neurological diseases. To develop treatments, we need to understand the precise choreography of these critical biochemical changes. However, the tiny size of the synaptic compartment makes precise measurements of the biochemical reactions impossible. We have used computer simulation techniques and information gathered from experiments on purified synaptic proteins to simulate, within a single synapse, the choreography of the first biochemical step in synaptic strengthening: activation of the enzyme Ca 2+ / calmodulin-dependent protein kinase II. Our results provide insights that can be used in future studies to develop treatments for neuronal diseases.
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Su JF, Xiao Y, Wei LY, Lei HY, Sun F, Wang WX, Li SH, Wang XC, Zheng J, Wang JZ. A new tau dephosphorylation-targeting chimera for the treatment of tauopathies. Acta Pharmacol Sin 2024:10.1038/s41401-024-01326-4. [PMID: 38956416 DOI: 10.1038/s41401-024-01326-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 05/26/2024] [Indexed: 07/04/2024] Open
Abstract
Abnormal accumulation of hyperphosphorylated tau protein plays a pivotal role in a collection of neurodegenerative diseases named tauopathies, including Alzheimer's disease (AD). We have recently conceptualized the design of hetero-bifunctional chimeras for selectively promoting the proximity between tau and phosphatase, thus specifically facilitating tau dephosphorylation and removal. Here, we sought to optimize the construction of tau dephosphorylating-targeting chimera (DEPTAC) and obtained a new chimera D14, which had high efficiency in reducing tau phosphorylation both in cell and tauopathy mouse models, while showing limited cytotoxicity. Moreover, D14 ameliorated neurodegeneration in primary cultured hippocampal neurons treated with toxic tau-K18 fragments, and improved cognitive functions of tauopathy mice. These results suggested D14 as a cost-effective drug candidate for the treatment of tauopathies.
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Affiliation(s)
- Jing-Fen Su
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yue Xiao
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Lin-Yu Wei
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, 453003, China
| | - Hui-Yang Lei
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Fei Sun
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wei-Xia Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Shi-Hong Li
- Department of Anesthesiology, the First Affiliated Hospital of Gannan Medical University, Ganzhou, 341000, China
| | - Xiao-Chuan Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Jie Zheng
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University; Key Laboratory for Neuroscience, Ministry of Education/National Health Commission, Peking University, Beijing, 100083, China.
- Beijing Life Science Academy, Beijing, 102209, China.
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226000, China.
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9
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Zhou C, Tang F, Dong T, Liu HB, Deng L, Margolis RL, Li PP. Role of Bβ1 overexpression in the pathogenesis of SCA12. Mov Disord 2024. [PMID: 38798069 DOI: 10.1002/mds.29839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 04/14/2024] [Accepted: 05/07/2024] [Indexed: 05/29/2024] Open
Abstract
BACKGROUND Spinocerebellar ataxia type 12 (SCA12) is a neurodegenerative disease caused by a CAG/CTG repeat expansion at the PPP2R2B locus. OBJECTIVE We investigated how the CAG repeat expansion within the PPP2R2B 7B7D transcript influences the expression of Bβ1 and a potential protein containing a long polyserine tract. METHODS Transcript and protein expression were measured using quantitative PCR (qPCR) Role of Bβ1 overexpression in the pathogenesis of SCA12 and Western blot, respectively, in an SK-N-MC cell model that overexpresses the full-length PPP2R2B 7B7D transcript. The apoptotic effect of a protein containing a long polyserine tract on SK-N-MC cells was evaluated using caspase 3/7 activity. RESULTS The CAG repeat expansion increases the expression of the PPP2R2B 7B7D transcript, as well as Bβ1 protein, in an SK-N-MC cell model in which the full-length PPP2R2B 7B7D transcript is overexpressed. The CAG repeat expansion within the 7B7D transcript is translated into a long polyserine tract that triggers apoptosis in SK-N-MC cells. CONCLUSIONS The SCA12 mutation leads to overexpression of PPP2R2B Bβ1 and to expression of a protein containing a long polyserine tract; both these effects potentially contribute to SCA12 pathogenesis. © 2024 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Chengqian Zhou
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Fan Tang
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Tao Dong
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hans B Liu
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Leon Deng
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Russell L Margolis
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Pan P Li
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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10
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Manoharan SD, Abdul Hamid H, Md Hashim NF, Cheema MS, Chiroma SM, Mustapha M, Mehat MZ. Could protein phosphatase 2A and glycogen synthase kinase-3 beta be targeted by natural compounds to ameliorate Alzheimer's pathologies? Brain Res 2024; 1829:148793. [PMID: 38309553 DOI: 10.1016/j.brainres.2024.148793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 12/26/2023] [Accepted: 01/29/2024] [Indexed: 02/05/2024]
Abstract
Alzheimer's disease (AD) is a progressive neurological disorder that impairs memory and cognitive abilities, primarily in the elderly. The burden of AD extends beyond patients, impacting families and caregivers due to the patients' reliance on assistance for daily tasks. The main features of the pathogenesis of AD are beta-amyloid plaques and neurofibrillary tangles (NFTs), that strongly correlate with oxidative stress and inflammation. NFTs result from misfolded and hyperphosphorylated tau proteins. Various studies have focused on tau phosphorylation, indicating protein phosphatase 2A (PP2A) as the primary tau phosphatase and glycogen synthase kinase-3 beta (GSK-3β) as the leading tau kinase. Experimental evidence suggests that inhibition of PP2A and increased GSK-3β activity contribute to neuroinflammation, oxidative stress, and cognitive impairment. Hence, targeting PP2A and GSK-3β with pharmacological approaches shows promise in treating AD. The use of natural compounds in the drug development for AD have been extensively studied for their antioxidant, anti-inflammatory, anti-cholinesterase, and neuroprotective properties, demonstrating therapeutic advantages in neurological diseases. Alongside the development of PP2A activator and GSK-3β inhibitor drugs, natural compounds are likely to have neuroprotective effects by increasing PP2A activity and decreasing GSK-3β levels. Therefore, based on the preclinical and clinical studies, the potential of PP2A and GSK-3β as therapeutic targets of natural compounds are highlighted in this review.
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Affiliation(s)
- Sushmitaa Dhevii Manoharan
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Hafizah Abdul Hamid
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Nur Fariesha Md Hashim
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Manraj Singh Cheema
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Samaila Musa Chiroma
- Newcastle University Medicine Malaysia (NUMed), Iskandar Puteri 79200, Johor, Malaysia.
| | - Muzaimi Mustapha
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia.
| | - Muhammad Zulfadli Mehat
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
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11
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Ganga AK, Sweeney LK, Ramos AR, Bishop CS, Hamel V, Guichard P, Breslow DK. A disease-associated PPP2R3C-MAP3K1 phospho-regulatory module controls centrosome function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.02.587836. [PMID: 38617270 PMCID: PMC11014585 DOI: 10.1101/2024.04.02.587836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Centrosomes have critical roles in microtubule organization and in cell signaling.1-8 However, the mechanisms that regulate centrosome function are not fully defined, and thus how defects in centrosomal regulation contribute to disease is incompletely understood. From functional genomic analyses, we find here that PPP2R3C, a PP2A phosphatase subunit, is a distal centriole protein and functional partner of centriolar proteins CEP350 and FOP. We further show that a key function of PPP2R3C is to counteract the kinase activity of MAP3K1. In support of this model, MAP3K1 knockout suppresses growth defects caused by PPP2R3C inactivation, and MAP3K1 and PPP2R3C have opposing effects on basal and microtubule stress-induced JNK signaling. Illustrating the importance of balanced MAP3K1 and PPP2R3C activities, acute overexpression of MAP3K1 severely inhibits centrosome function and triggers rapid centriole disintegration. Additionally, inactivating PPP2R3C mutations and activating MAP3K1 mutations both cause congenital syndromes characterized by gonadal dysgenesis.9-15 As a syndromic PPP2R3C variant is defective in centriolar localization and binding to centriolar protein FOP, we propose that imbalanced activity of this centrosomal kinase-phosphatase pair is the shared cause of these disorders. Thus, our findings reveal a new centrosomal phospho-regulatory module, shed light on disorders of gonadal development, and illustrate the power of systems genetics to identify previously unrecognized gene functions.
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Affiliation(s)
- Anil Kumar Ganga
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Lauren K. Sweeney
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Armando Rubio Ramos
- Department of Molecular and Cellular Biology, University of Geneva, Faculty of Sciences, Geneva, Switzerland
| | - Cassandra S. Bishop
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, University of Geneva, Faculty of Sciences, Geneva, Switzerland
| | - Paul Guichard
- Department of Molecular and Cellular Biology, University of Geneva, Faculty of Sciences, Geneva, Switzerland
| | - David K. Breslow
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
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12
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Brewer A, Sathe G, Pflug BE, Clarke RG, Macartney TJ, Sapkota GP. Mapping the substrate landscape of protein phosphatase 2A catalytic subunit PPP2CA. iScience 2024; 27:109302. [PMID: 38450154 PMCID: PMC10915630 DOI: 10.1016/j.isci.2024.109302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/18/2023] [Accepted: 02/16/2024] [Indexed: 03/08/2024] Open
Abstract
Protein phosphatase 2A (PP2A) is an essential Ser/Thr phosphatase. The PP2A holoenzyme complex comprises a scaffolding (A), regulatory (B), and catalytic (C) subunit, with PPP2CA being the principal catalytic subunit. The full scope of PP2A substrates in cells remains to be defined. To address this, we employed dTAG proteolysis-targeting chimeras to efficiently and selectively degrade dTAG-PPP2CA in homozygous knock-in HEK293 cells. Unbiased global phospho-proteomics identified 2,204 proteins with significantly increased phosphorylation upon dTAG-PPP2CA degradation, implicating them as potential PPP2CA substrates. A vast majority of these are novel. Bioinformatic analyses revealed involvement of the potential PPP2CA substrates in spliceosome function, cell cycle, RNA transport, and ubiquitin-mediated proteolysis. We identify a pSP/pTP motif as a predominant target for PPP2CA and confirm some of our phospho-proteomic data with immunoblotting. We provide an in-depth atlas of potential PPP2CA substrates and establish targeted degradation as a robust tool to unveil phosphatase substrates in cells.
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Affiliation(s)
- Abigail Brewer
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gajanan Sathe
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Billie E. Pflug
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Rosemary G. Clarke
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Thomas J. Macartney
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gopal P. Sapkota
- Medical Research Council (MRC) Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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13
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Kim EY, Verdejo-Torres O, Diaz-Rodriguez K, Hasanain F, Caromile L, Padilla-Benavides T. Single nucleotide polymorphisms and Zn transport by ZIP11 shape functional phenotypes of HeLa cells. Metallomics 2024; 16:mfae006. [PMID: 38285610 DOI: 10.1093/mtomcs/mfae006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 01/27/2024] [Indexed: 01/31/2024]
Abstract
Zinc (Zn) is a vital micronutrient with essential roles in biological processes like enzyme function, gene expression, and cell signaling. Disruptions in the cellular regulation of Zn2+ ions often lead to pathological states. Mammalian Zn transporters, such as ZIP11, play a key role in homeostasis of this ion. ZIP11 resides predominately in the nucleus and Golgi apparatus. Our laboratory reported a function of ZIP11 in maintaining nuclear Zn levels in HeLa cervical cancer cells. Analyses of cervical and ovarian cancer patients' datasets identified four coding, single nucleotide polymorphisms (SNPs) in SLC39A11, the gene that encodes ZIP11, correlating with disease severity. We hypothesized that these SNPs might translate to functional changes in the ZIP11 protein by modifying access to substrate availability. We also proposed that a metal-binding site (MBS) in ZIP11 is crucial for transmembrane Zn2+ transport and required for maintenance of various pathogenic phenotypes observed in HeLa cells. Here, we investigated these claims by re-introducing single the SLC39A11 gene encoding for mutant residues associated with the SNPs, as well as MBS mutations into HeLa cells knocked down for the transporter. Some SNPs-encoding ZIP11 variants rescued Zn levels, proliferation, migration, and invasiveness of knockdown (KD) cells. Conversely, single MBS mutations mimicked the traits of KD cells, confirming the transporter's role in establishing and maintaining proliferative, migratory, and invasive traits. Overall, the intricate role of Zn in cellular dynamics and cancer progression underscores the significance of Zn transporters like ZIP11 in potential therapeutic interventions.
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Affiliation(s)
- Elizabeth Y Kim
- Department of Molecular Biology & Biochemistry, Wesleyan University, 52 Lawn Ave., Middletown, CT 06459, USA
| | - Odette Verdejo-Torres
- Department of Molecular Biology & Biochemistry, Wesleyan University, 52 Lawn Ave., Middletown, CT 06459, USA
| | - Karla Diaz-Rodriguez
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 60 Prescott St., Worcester, MA 01605, USA
| | - Farah Hasanain
- Department of Molecular Biology & Biochemistry, Wesleyan University, 52 Lawn Ave., Middletown, CT 06459, USA
| | - Leslie Caromile
- Departmentof Cell Biology, Center for Vascular Biology, UCONN Health-Center, Farmington, CT 06030, USA
| | - Teresita Padilla-Benavides
- Department of Molecular Biology & Biochemistry, Wesleyan University, 52 Lawn Ave., Middletown, CT 06459, USA
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14
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Fujiwara K, Maekawa M, Iimori Y, Ogawa A, Urano T, Kono N, Takeda H, Higashiyama S, Arita M, Murai J. The crucial role of single-stranded DNA binding in enhancing sensitivity to DNA-damaging agents for Schlafen 11 and Schlafen 13. iScience 2023; 26:108529. [PMID: 38125019 PMCID: PMC10730379 DOI: 10.1016/j.isci.2023.108529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/19/2023] [Accepted: 11/20/2023] [Indexed: 12/23/2023] Open
Abstract
Schlafen (SLFN) 11 enhances cellular sensitivity to various DNA-damaging anticancer agents. Among the human SLFNs (SLFN5/11/12/13/14), SLFN11 is unique in its drug sensitivity and ability to block replication under DNA damage. In biochemical analysis, SLFN11 binds single-stranded DNA (ssDNA), and this binding is enhanced by the dephosphorylation of SLFN11. In this study, human cell-based assays demonstrated that a point mutation at the ssDNA-binding site of SLFN11 or a constitutive phosphorylation mutant abolished SLFN11-dependent drug sensitivity. Additionally, we discovered that nuclear SLFN13 with a point mutation mimicking the DNA-binding site of SLFN11 was recruited to chromatin, blocked replication, and enhanced drug sensitivity. Through generating multiple mutants and structure analyses of SLFN11 and SLFN13, we identified protein phosphatase 2A as a binding partner of SLFN11 and the putative binding motif in SLFN11. These findings provide crucial insights into the unique characteristics of SLFN11, contributing to a better understanding of its mechanisms.
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Affiliation(s)
- Kohei Fujiwara
- Division of Physiological Chemistry and Metabolism, Graduate School of Pharmaceutical Sciences, Keio University, Minato-Ku, Tokyo 105-8512, Japan
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa 230-0045, Japan
| | - Masashi Maekawa
- Division of Physiological Chemistry and Metabolism, Graduate School of Pharmaceutical Sciences, Keio University, Minato-Ku, Tokyo 105-8512, Japan
| | - Yuki Iimori
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
| | - Akane Ogawa
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
| | - Takeshi Urano
- Department of Biochemistry, Faculty of Medicine, Shimane University, Izumo, Shimane 693-8501, Japan
- Center for Vaccines and Therapeutic Antibodies for Emerging Infectious Diseases, Shimane University, Izumo, Shimane 693-8501, Japan
| | - Nobuaki Kono
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, Kanagawa 252-0882, Japan
| | - Hiroyuki Takeda
- Division of Proteo-Drug-Discovery, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Shigeki Higashiyama
- Division of Cell Growth and Tumor Regulation, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan
- Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan
- Department of Oncogenesis and Tumor Regulation, Osaka International Cancer Institute, Chuo-Ku, Osaka 541-8567, Japan
| | - Makoto Arita
- Division of Physiological Chemistry and Metabolism, Graduate School of Pharmaceutical Sciences, Keio University, Minato-Ku, Tokyo 105-8512, Japan
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa 230-0045, Japan
- Human Biology-Microbiome-Quantum Research Center (WPI-Bio2Q), Keio University, Tokyo, Japan
- Cellular and Molecular Epigenetics Laboratory, Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa 230-0045, Japan
| | - Junko Murai
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
- Division of Cell Growth and Tumor Regulation, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan
- Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan
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15
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Ostrožovičová M, Mecheri Y, Al-Mubarak BR, Al-Tassan N, Makarious MB, Periñan MT, Bandres-Ciga S. PTPA variants and the risk for Parkinson's disease in diverse ancestry populations. Brain 2023; 146:e120-e124. [PMID: 37467482 PMCID: PMC10689897 DOI: 10.1093/brain/awad247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/06/2023] [Indexed: 07/21/2023] Open
Affiliation(s)
- Miriam Ostrožovičová
- Department of Neurology, P.J. Safarik University, Kosice 04011, Slovak Republic
- Department of Neurology, University Hospital of L. Pasteur, Kosice 04011, Slovak Republic
| | - Yasser Mecheri
- Neurology Department, Dr Benbadis University Hospital, Constantine 25018, Algeria
| | - Bashayer R Al-Mubarak
- Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Nada Al-Tassan
- Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Mary B Makarious
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
- UCL Movement Disorders Centre, University College London, WC1N 3BG London, UK
| | - Maria Teresa Periñan
- Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiología Clínica, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Sevilla, 41013 Seville, Spain
- Preventive Neurology Unit, Centre for Prevention, Detection and Diagnosis, Wolfson Institute of Population Health, Queen Mary University of London, EC1M 6BQ London, UK
| | - Sara Bandres-Ciga
- Center for Alzheimer’s and Related Dementias (CARD), National Institute on Aging and National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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16
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Yu J, Zhao Y, Gong XK, Liang Z, Zhao YN, Li X, Chen YJ, Yang YH, Wu MJ, Wang XC, Shu XJ, Bao J. P25/CDK5-mediated Tau Hyperphosphorylation in Both Ipsilateral and Contralateral Cerebra Contributes to Cognitive Deficits in Post-stroke Mice. Curr Med Sci 2023; 43:1084-1095. [PMID: 37924385 DOI: 10.1007/s11596-023-2792-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 08/16/2023] [Indexed: 11/06/2023]
Abstract
OBJECTIVE Post-stroke cognitive impairment (PSCI) develops in approximately one-third of stroke survivors and is associated with ingravescence. Nonetheless, the biochemical mechanisms underlying PSCI remain unclear. The study aimed to establish an ischemic mouse model by means of transient unilateral middle cerebral artery occlusions (MCAOs) and to explore the biochemical mechanisms of p25/cyclin-dependent kinase 5 (CDK5)-mediated tau hyperphosphorylation on the PSCI behavior. METHODS Cognitive behavior was investigated, followed by the detection of tau hyperphosphorylation, mobilization, activation of kinases and/or inhibition of phosphatases in the lateral and contralateral cerebrum of mice following ischemia in MACO mice. Finally, we treated HEK293/tau cells with oxygen-glucose deprivation (OGD) and a CDK5 inhibitor (Roscovitine) or a GSK3β inhibitor (LiCl) to the roles of CDK5 and GSK3β in mediating ischemia-reperfusion-induced tau phosphorylation. RESULTS Ischemia induced cognitive impairments within 2 months, as well as causing tau hyperphosphorylation and its localization to neuronal somata in both ipsilateral and contralateral cerebra. Furthermore, p25 that promotes CDK5 hyperactivation had significantly higher expression in the mice with MCAO than in the shamoperation (control) group, while the expression levels of protein phosphatase 2 (PP2A) and the phosphorylation level at Tyr307 were comparable between the two groups. In addition, the CDK5 inhibitor rescued tau from hyperphosphorylation induced by OGD. CONCLUSION These findings demonstrate that upregulation of CDK5 mediates tau hyperphosphorylation and localization in both ipsilateral and contralateral cerebra, contributing to the pathogenesis of PSCI.
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Affiliation(s)
- Jing Yu
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan, 430056, China
| | - Yang Zhao
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
| | - Xiao-Kang Gong
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
| | - Zheng Liang
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
| | - Yan-Na Zhao
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan, 430056, China
| | - Xin Li
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan, 430056, China
| | - Yu-Ju Chen
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan, 430056, China
| | - You-Hua Yang
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan, 430056, China
| | - Meng-Juan Wu
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan, 430056, China
| | - Xiao-Chuan Wang
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xi-Ji Shu
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China.
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan, 430056, China.
| | - Jian Bao
- Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China.
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan, 430056, China.
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17
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DeMarco AG, Dibble MG, Hall MC. Inducible degradation-coupled phosphoproteomics identifies PP2A Rts1 as a novel eisosome regulator. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563668. [PMID: 37961087 PMCID: PMC10634780 DOI: 10.1101/2023.10.24.563668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Reversible protein phosphorylation is an abundant post-translational modification dynamically regulated by opposing kinases and phosphatases. Protein phosphorylation has been extensively studied in cell division, where waves of cyclin-dependent kinase activity, peaking in mitosis, drive the sequential stages of the cell cycle. Here we developed and employed a strategy to specifically probe kinase or phosphatase substrates at desired times or experimental conditions in the model organism Saccharomyces cerevisiae. We combined auxin-inducible degradation (AID) with mass spectrometry-based phosphoproteomics, which allowed us to arrest physiologically normal cultures in mitosis prior to rapid phosphatase degradation and phosphoproteome analysis. Our results revealed that protein phosphatase 2A coupled with its B56 regulatory subunit, Rts1 (PP2ARts1), is involved in dephosphorylation of numerous proteins in mitosis, highlighting the need for phosphatases to selectively maintain certain proteins in a hypophosphorylated state in the face of high mitotic kinase activity. Unexpectedly, we observed elevated phosphorylation at many sites on several subunits of the fungal eisosome complex following rapid Rts1 degradation. Eisosomes are dynamic polymeric assemblies that create furrows in the plasma membrane important in regulating nutrient import, lipid metabolism, and stress responses, among other things. We found that PP2ARts1-mediated dephosphorylation of eisosomes promotes their plasma membrane association and we provide evidence that this regulation impacts eisosome roles in metabolic homeostasis. The combination of rapid, inducible protein degradation with proteomic profiling offers several advantages over common protein disruption methods for characterizing substrates of regulatory enzymes involved in dynamic biological processes.
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Affiliation(s)
- Andrew G. DeMarco
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907
| | - Marcella G. Dibble
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907
| | - Mark C. Hall
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907
- Institute for Cancer Research, Purdue University, West Lafayette, IN, 47907
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18
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Roldán M, Nolasco GA, Armengol L, Frías M, Morell M, García-Aragonés M, Epifani F, Muchart J, Ramírez-Almaraz ML, Martorell L, Hernando-Davalillo C, Urreizti R, Serrano M. Advanced Optical Microscopy: Unveiling Functional Insights Regarding a Novel PPP2R1A Variant and Its Unreported Phenotype. Int J Mol Sci 2023; 24:13699. [PMID: 37762002 PMCID: PMC10530954 DOI: 10.3390/ijms241813699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/30/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023] Open
Abstract
The number of genes implicated in neurodevelopmental conditions is rapidly growing. Recently, variants in PPP2R1A have been associated with syndromic intellectual disability and a consistent, but still expanding, phenotype. The PPP2R1A gene encodes a protein subunit of the serine/threonine protein phosphatase 2A enzyme, which plays a critical role in cellular function. We report an individual showing pontocerebellar hypoplasia (PCH), microcephaly, optic and peripheral nerve abnormalities, and an absence of typical features like epilepsy and an abnormal corpus callosum. He bears an unreported variant in an atypical region of PPP2R1A. In silico studies, functional analysis using immunofluorescence, and super-resolution microscopy techniques were performed to investigate the pathogenicity of the variant. This analysis involved a comparative analysis of the patient's fibroblasts with both healthy control cells and cells from an individual with the previously described phenotype. The results showed reduced expression of PPP2R1A and the presence of aberrant protein aggregates in the patient's fibroblasts, supporting the pathogenicity of the variant. These findings suggest a potential association between PPP2R1A variants and PCH, expanding the clinical spectrum of PPP2R1A-related neurodevelopmental disorder. Further studies and descriptions of additional patients are needed to fully understand the genotype-phenotype correlation and the underlying mechanisms of this novel phenotype.
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Affiliation(s)
- Mònica Roldán
- Confocal Microscopy and Cellular Imaging Unit, Genetic and Molecular Medicine Department, Pediatric Institute for Rare Diseases, Hospital Sant Joan de Déu, 08950 Barcelona, Spain; (M.R.); (M.F.)
- Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain; (G.A.N.); (F.E.); (J.M.); (L.M.); (C.H.-D.); (R.U.)
| | - Gregorio Alexander Nolasco
- Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain; (G.A.N.); (F.E.); (J.M.); (L.M.); (C.H.-D.); (R.U.)
- Pediatric Neurology Department, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Lluís Armengol
- Quantitative Genomic Medicine Laboratories, qGenomics, 08950 Barcelona, Spain; (L.A.); (M.M.); (M.G.-A.)
| | - Marcos Frías
- Confocal Microscopy and Cellular Imaging Unit, Genetic and Molecular Medicine Department, Pediatric Institute for Rare Diseases, Hospital Sant Joan de Déu, 08950 Barcelona, Spain; (M.R.); (M.F.)
- Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain; (G.A.N.); (F.E.); (J.M.); (L.M.); (C.H.-D.); (R.U.)
| | - Marta Morell
- Quantitative Genomic Medicine Laboratories, qGenomics, 08950 Barcelona, Spain; (L.A.); (M.M.); (M.G.-A.)
| | - Manel García-Aragonés
- Quantitative Genomic Medicine Laboratories, qGenomics, 08950 Barcelona, Spain; (L.A.); (M.M.); (M.G.-A.)
| | - Florencia Epifani
- Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain; (G.A.N.); (F.E.); (J.M.); (L.M.); (C.H.-D.); (R.U.)
- Pediatric Neurology Department, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Jordi Muchart
- Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain; (G.A.N.); (F.E.); (J.M.); (L.M.); (C.H.-D.); (R.U.)
- Diagnostic Imaging Department, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - María Luisa Ramírez-Almaraz
- Genetic and Molecular Medicine Department, Pediatric Institute for Rare Diseases, Hospital Sant Joan de Déu, 08950 Barcelona, Spain;
| | - Loreto Martorell
- Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain; (G.A.N.); (F.E.); (J.M.); (L.M.); (C.H.-D.); (R.U.)
- Genetic and Molecular Medicine Department, Pediatric Institute for Rare Diseases, Hospital Sant Joan de Déu, 08950 Barcelona, Spain;
| | - Cristina Hernando-Davalillo
- Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain; (G.A.N.); (F.E.); (J.M.); (L.M.); (C.H.-D.); (R.U.)
- Genetic and Molecular Medicine Department, Pediatric Institute for Rare Diseases, Hospital Sant Joan de Déu, 08950 Barcelona, Spain;
| | - Roser Urreizti
- Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain; (G.A.N.); (F.E.); (J.M.); (L.M.); (C.H.-D.); (R.U.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBER-ER), Instituto de Salud Carlos III, 28220 Barcelona, Spain
- Clinical Biochemistry Department, Hospital Sant Joan de Deu, 08950 Barcelona, Spain
| | - Mercedes Serrano
- Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain; (G.A.N.); (F.E.); (J.M.); (L.M.); (C.H.-D.); (R.U.)
- Pediatric Neurology Department, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBER-ER), Instituto de Salud Carlos III, 28220 Barcelona, Spain
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19
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Qian Y, Jiang Y, Wang J, Li G, Wu B, Zhou Y, Xu X, Wang H. Novel Variants of PPP2R1A in Catalytic Subunit Binding Domain and Genotype-Phenotype Analysis in Neurodevelopmentally Delayed Patients. Genes (Basel) 2023; 14:1750. [PMID: 37761890 PMCID: PMC10531206 DOI: 10.3390/genes14091750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/26/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023] Open
Abstract
Neurodevelopmental disorders (NDDs) are a group of high-incidence rare diseases with genetic heterogeneity. PPP2R1A, the regulatory subunit of protein phosphatase 2A, is a recently discovered gene associated with NDDs. Whole/clinical exome sequencing was performed in five patients with a family with NDDs. In vitro experiments were performed to evaluate the mutants' expression and interactions with the complex. The genotype-phenotype correlations of reported cases as well as our patients with PPP2R1A variants were reviewed. We reported five unrelated individuals with PPP2R1A variants, including two novel missense variants and one frameshift variant. The protein expression of the Arg498Leu variant was less than that of the wild-type protein, the frameshift variant Asn282Argfs*14 was not decreased but truncated, and these two variants impaired the interactions with endogenous PPP25RD and PPP2CA. Furthermore, we found that pathogenic variants clustered in HEAT repeats V, VI and VII, and patients with the Met180Val/Thr variants had macrocephaly, severe ID and hypotonia, but no epilepsy, whereas those with Arg258 amino acid changes had microcephaly, while a few had epilepsy or feeding problems. In this study, we reported five NDD patients with PPP2R1A gene variants and expanded PPP2R1A pathogenic variant spectrum. The genotype and phenotype association findings provide reminders regarding the prognostication and evidence for genetic counseling.
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Affiliation(s)
- Yanyan Qian
- Center for Molecular Medicine, Pediatrics Research Institute, Children’s Hospital of Fudan University, National Children’s Medical Center, 399 Wanyuan Road, Shanghai 201102, China; (Y.Q.); (Y.J.); (G.L.); (B.W.)
| | - Yinmo Jiang
- Center for Molecular Medicine, Pediatrics Research Institute, Children’s Hospital of Fudan University, National Children’s Medical Center, 399 Wanyuan Road, Shanghai 201102, China; (Y.Q.); (Y.J.); (G.L.); (B.W.)
| | - Ji Wang
- Neurology Department, Children’s Hospital of Fudan University, National Children’s Medical Center, 399 Wanyuan Road, Shanghai 201102, China; (J.W.); (Y.Z.)
| | - Gang Li
- Center for Molecular Medicine, Pediatrics Research Institute, Children’s Hospital of Fudan University, National Children’s Medical Center, 399 Wanyuan Road, Shanghai 201102, China; (Y.Q.); (Y.J.); (G.L.); (B.W.)
| | - Bingbing Wu
- Center for Molecular Medicine, Pediatrics Research Institute, Children’s Hospital of Fudan University, National Children’s Medical Center, 399 Wanyuan Road, Shanghai 201102, China; (Y.Q.); (Y.J.); (G.L.); (B.W.)
| | - Yuanfeng Zhou
- Neurology Department, Children’s Hospital of Fudan University, National Children’s Medical Center, 399 Wanyuan Road, Shanghai 201102, China; (J.W.); (Y.Z.)
| | - Xiu Xu
- Department of Child Health Care, Children’s Hospital of Fudan University, National Children’s Medical Center, 399 Wanyuan Road, Shanghai 201102, China
| | - Huijun Wang
- Center for Molecular Medicine, Pediatrics Research Institute, Children’s Hospital of Fudan University, National Children’s Medical Center, 399 Wanyuan Road, Shanghai 201102, China; (Y.Q.); (Y.J.); (G.L.); (B.W.)
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20
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Smolen KA, Papke CM, Swingle MR, Musiyenko A, Li C, Salter EA, Camp AD, Honkanen RE, Kettenbach AN. Quantitative proteomics and phosphoproteomics of PP2A-PPP2R5D variants reveal deregulation of RPS6 phosphorylation via converging signaling cascades. J Biol Chem 2023; 299:105154. [PMID: 37572851 PMCID: PMC10485637 DOI: 10.1016/j.jbc.2023.105154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 07/28/2023] [Accepted: 07/29/2023] [Indexed: 08/14/2023] Open
Abstract
Genetic germline variants of PPP2R5D (encoding: phosphoprotein phosphatase 2 regulatory protein 5D) result in PPP2R5D-related disorder (Jordan's Syndrome), which is characterized by intellectual disability, hypotonia, seizures, macrocephaly, autism spectrum disorder, and delayed motor skill development. The disorder originates from de novo single nucleotide mutations, generating missense variants that act in a dominant manner. Pathogenic mutations altering 13 different amino acids have been identified, with the E198K variant accounting for ∼40% of reported cases. However, the generation of a heterozygous E198K variant cell line to study the molecular effects of the pathogenic mutation has been challenging. Here, we use CRISPR-PRIME genomic editing to introduce a transition (c.592G>A) in a single PPP2R5D allele in HEK293 cells, generating E198K-heterozygous lines to complement existing E420K variant lines. We generate global protein and phosphorylation profiles of WT, E198K, and E420K cell lines and find unique and shared changes between variants and WT cells in kinase- and phosphatase-controlled signaling cascades. We observed ribosomal protein S6 (RPS6) hyperphosphorylation as a shared signaling alteration, indicative of increased ribosomal protein S6-kinase activity. Treatment with rapamycin or an RPS6-kinase inhibitor (LY2584702) suppressed RPS6 phosphorylation in both, suggesting upstream activation of mTORC1/p70S6K. Intriguingly, our data suggests ERK-dependent activation of mTORC1 in both E198K and E420K variant cells, with additional AKT-mediated mTORC1 activation in the E420K variant. Thus, although upstream activation of mTORC1 differs between PPP2R5D-related disorder genotypes, inhibition of mTORC1 or RPS6 kinases warrants further investigation as potential therapeutic strategies for patients.
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Affiliation(s)
- Kali A Smolen
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Cinta M Papke
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Mark R Swingle
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Alla Musiyenko
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Chenchen Li
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - E Alan Salter
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Ashley D Camp
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Richard E Honkanen
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA.
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA; Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA.
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21
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Vertyshev AY, Akberdin IR, Kolpakov FA. Numerous Trigger-like Interactions of Kinases/Protein Phosphatases in Human Skeletal Muscles Can Underlie Transient Processes in Activation of Signaling Pathways during Exercise. Int J Mol Sci 2023; 24:11223. [PMID: 37446402 DOI: 10.3390/ijms241311223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Optimizing physical training regimens to increase muscle aerobic capacity requires an understanding of the internal processes that occur during exercise that initiate subsequent adaptation. During exercise, muscle cells undergo a series of metabolic events that trigger downstream signaling pathways and induce the expression of many genes in working muscle fibers. There are a number of studies that show the dependence of changes in the activity of AMP-activated protein kinase (AMPK), one of the mediators of cellular signaling pathways, on the duration and intensity of single exercises. The activity of various AMPK isoforms can change in different directions, increasing for some isoforms and decreasing for others, depending on the intensity and duration of the load. This review summarizes research data on changes in the activity of AMPK, Ca2+/calmodulin-dependent protein kinase II (CaMKII), and other components of the signaling pathways in skeletal muscles during exercise. Based on these data, we hypothesize that the observed changes in AMPK activity may be largely related to metabolic and signaling transients rather than exercise intensity per se. Probably, the main events associated with these transients occur at the beginning of the exercise in a time window of about 1-10 min. We hypothesize that these transients may be partly due to putative trigger-like kinase/protein phosphatase interactions regulated by feedback loops. In addition, numerous dynamically changing factors, such as [Ca2+], metabolite concentration, and reactive oxygen and nitrogen species (RONS), can shift the switching thresholds and change the states of these triggers, thereby affecting the activity of kinases (in particular, AMPK and CaMKII) and phosphatases. The review considers the putative molecular mechanisms underlying trigger-like interactions. The proposed hypothesis allows for a reinterpretation of the experimental data available in the literature as well as the generation of ideas to optimize future training regimens.
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Affiliation(s)
| | - Ilya R Akberdin
- Department of Computational Biology, Scientific Center for Information Technologies and Artificial Intelligence, Sirius University of Science and Technology, 354340 Sochi, Russia
- Biosoft.Ru, Ltd., 630058 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Fedor A Kolpakov
- Department of Computational Biology, Scientific Center for Information Technologies and Artificial Intelligence, Sirius University of Science and Technology, 354340 Sochi, Russia
- Biosoft.Ru, Ltd., 630058 Novosibirsk, Russia
- Federal Research Center for Information and Computational Technologies, 630090 Novosibirsk, Russia
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22
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Salter EA, Wierzbicki A, Honkanen RE, Swingle MR. Quantum-based modeling implies that bidentate Arg 89-substrate binding enhances serine/threonine protein phosphatase-2A(PPP2R5D/PPP2R1A/PPP2CA)-mediated dephosphorylation. Front Cell Dev Biol 2023; 11:1141804. [PMID: 37377738 PMCID: PMC10291244 DOI: 10.3389/fcell.2023.1141804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
PP2A-serine/threonine protein phosphatases function as heterotrimeric holoenzymes, composed of a common scaffold (A-subunit encoded by PPP2R1A/PPP2R1B), a common catalytic (C-subunit encoded by PPP2CA/PPP2CB), and one of many variable regulatory (B) subunits. The site of phosphoprotein phosphatase (PPP) hydrolysis features a bimetal system (M1/M2), an associated bridge hydroxide [W1(OH-)], and a highly-conserved core sequence. In the presumptive common mechanism, the phosphoprotein's seryl/threonyl phosphate coordinates the M1/M2 system, W1(OH-) attacks the central P atom, rupturing the antipodal bond, and simultaneously, a histidine/aspartate tandem protonates the exiting seryl/threonyl alkoxide. Based on studies of PPP5C, a conserved arginine proximal to M1 is also expected to bind the substrate's phosphate group in a bidentate fashion. However, in PP2A isozymes, the role of the arginine (Arg89) in hydrolysis is not clear because two independent structures for PP2A(PPP2R5C) and PP2A(PPP2R5D) show that Arg89 engages in a weak salt bridge at the B:C interface. These observations raise the question of whether hydrolysis proceeds with or without direct involvement of Arg89. The interaction of Arg89 with B:Glu198 in PP2A(PPP2R5D) is significant because the pathogenic E198K variant of B56δ is associated with irregular protein phosphorylation levels and consequent developmental disorders (Jordan's Syndrome; OMIM #616355). In this study, we perform quantum-based hybrid [ONIOM(UB3LYP/6-31G(d):UPM7)] calculations on 39-residue models of the PP2A(PPP2R5D)/pSer (phosphoserine) system to estimate activation barriers for hydrolysis in the presence of bidentate Arg89-substrate binding and when Arg89 is otherwise engaged in the salt-bridge interaction. Our solvation-corrected results yield ΔH‡ ≈ ΔE‡ = +15.5 kcal/mol for the former case, versus +18.8 kcal/mol for the latter, indicating that bidentate Arg89-substrate binding is critical for optimal catalytic function of the enzyme. We speculate that PP2A(PPP2R5D) activity is suppressed by B:Glu198 sequestration of C:Arg89 under native conditions, whereas the PP2A(PPP2R5D)-holoenzyme containing the E198K variant has a positively-charged lysine in this position that alters normal function.
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Affiliation(s)
- E. Alan Salter
- Department of Chemistry, University of South Alabama, Mobile, AL, United States
| | - Andrzej Wierzbicki
- Department of Chemistry, University of South Alabama, Mobile, AL, United States
| | - Richard E. Honkanen
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL, United States
| | - Mark R. Swingle
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL, United States
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23
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Fevga C, Tesson C, Carreras Mascaro A, Courtin T, van Coller R, Sakka S, Ferraro F, Farhat N, Bardien S, Damak M, Carr J, Ferrien M, Boumeester V, Hundscheid J, Grillenzoni N, Kessissoglou IA, Kuipers DJS, Quadri M, Corvol JC, Mhiri C, Hassan BA, Breedveld GJ, Lesage S, Mandemakers W, Brice A, Bonifati V. PTPA variants and impaired PP2A activity in early-onset parkinsonism with intellectual disability. Brain 2023; 146:1496-1510. [PMID: 36073231 PMCID: PMC10115167 DOI: 10.1093/brain/awac326] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/24/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
The protein phosphatase 2A complex (PP2A), the major Ser/Thr phosphatase in the brain, is involved in a number of signalling pathways and functions, including the regulation of crucial proteins for neurodegeneration, such as alpha-synuclein, tau and LRRK2. Here, we report the identification of variants in the PTPA/PPP2R4 gene, encoding a major PP2A activator, in two families with early-onset parkinsonism and intellectual disability. We carried out clinical studies and genetic analyses, including genome-wide linkage analysis, whole-exome sequencing, and Sanger sequencing of candidate variants. We next performed functional studies on the disease-associated variants in cultured cells and knock-down of ptpa in Drosophila melanogaster. We first identified a homozygous PTPA variant, c.893T>G (p.Met298Arg), in patients from a South African family with early-onset parkinsonism and intellectual disability. Screening of a large series of additional families yielded a second homozygous variant, c.512C>A (p.Ala171Asp), in a Libyan family with a similar phenotype. Both variants co-segregate with disease in the respective families. The affected subjects display juvenile-onset parkinsonism and intellectual disability. The motor symptoms were responsive to treatment with levodopa and deep brain stimulation of the subthalamic nucleus. In overexpression studies, both the PTPA p.Ala171Asp and p.Met298Arg variants were associated with decreased PTPA RNA stability and decreased PTPA protein levels; the p.Ala171Asp variant additionally displayed decreased PTPA protein stability. Crucially, expression of both variants was associated with decreased PP2A complex levels and impaired PP2A phosphatase activation. PTPA orthologue knock-down in Drosophila neurons induced a significant impairment of locomotion in the climbing test. This defect was age-dependent and fully reversed by L-DOPA treatment. We conclude that bi-allelic missense PTPA variants associated with impaired activation of the PP2A phosphatase cause autosomal recessive early-onset parkinsonism with intellectual disability. Our findings might also provide new insights for understanding the role of the PP2A complex in the pathogenesis of more common forms of neurodegeneration.
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Affiliation(s)
- Christina Fevga
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Christelle Tesson
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
| | - Ana Carreras Mascaro
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Thomas Courtin
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
- Assistance Publique Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, Département de Génétique, DMU BioGeM, Paris, France
| | - Riaan van Coller
- Department of Neurology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Salma Sakka
- Research Unit in Neurogenetics, Clinical Investigation Center (CIC) at the CHU Habib Bourguiba, Sfax, Tunisia
| | - Federico Ferraro
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Nouha Farhat
- Research Unit in Neurogenetics, Clinical Investigation Center (CIC) at the CHU Habib Bourguiba, Sfax, Tunisia
| | - Soraya Bardien
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- South African Medical Research Council/Stellenbosch University Genomics of Brain Disorders Research Unit, Stellenbosch University, Cape Town, South Africa
| | - Mariem Damak
- Research Unit in Neurogenetics, Clinical Investigation Center (CIC) at the CHU Habib Bourguiba, Sfax, Tunisia
| | - Jonathan Carr
- Division of Neurology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Mélanie Ferrien
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
| | - Valerie Boumeester
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Jasmijn Hundscheid
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Nicola Grillenzoni
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
| | - Irini A Kessissoglou
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
| | - Demy J S Kuipers
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Marialuisa Quadri
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Jean-Christophe Corvol
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
- Assistance Publique Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, Département de Neurologie, Centre d'Investigation Clinique Neurosciences, DMU Neuroscience, Paris, France
| | - Chokri Mhiri
- Research Unit in Neurogenetics, Clinical Investigation Center (CIC) at the CHU Habib Bourguiba, Sfax, Tunisia
| | - Bassem A Hassan
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
| | - Guido J Breedveld
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Suzanne Lesage
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
| | - Wim Mandemakers
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Alexis Brice
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, Paris, France
- Assistance Publique Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, Département de Génétique, DMU BioGeM, Paris, France
| | - Vincenzo Bonifati
- Department of Clinical Genetics, Erasmus University Medical Center Rotterdam, Erasmus MC, 3015 GD Rotterdam, The Netherlands
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24
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KA S, CM P, Swingle MR, A M, C L, AD C, RE H, AN K. Quantitative proteomics and phosphoproteomics of PPP2R5D variants reveal deregulation of RPS6 phosphorylation through converging signaling cascades. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.27.534397. [PMID: 37034727 PMCID: PMC10081281 DOI: 10.1101/2023.03.27.534397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Variants in the phosphoprotein phosphatase-2 regulatory protein-5D gene ( PPP2R5D ) cause the clinical phenotype of Jordan's Syndrome (PPP2R5D-related disorder), which includes intellectual disability, hypotonia, seizures, macrocephaly, autism spectrum disorder and delayed motor skill development. The disorder originates from de novo single nucleotide mutations, generating missense variants that act in a dominant manner. Pathogenic mutations altering 13 different amino acids have been identified, with the E198K variant accounting for ∼40% of reported cases. Here, we use CRISPR-PRIME genomic editing to introduce a transition (c.592G>A) in the PPP2R5D allele in a heterozygous manner in HEK293 cells, generating E198K-heterozygous lines to complement existing E420K variant lines. We generate global protein and phosphorylation profiles of wild-type, E198K, and E420K cell lines and find unique and shared changes between variants and wild-type cells in kinase- and phosphatase-controlled signaling cascades. As shared signaling alterations, we observed ribosomal protein S6 (RPS6) hyperphosphorylation, indicative of increased ribosomal protein S6-kinase activity. Rapamycin treatment suppressed RPS6 phosphorylation in both, suggesting activation of mTORC1. Intriguingly, our data suggest AKT-dependent (E420K) and -independent (E198K) activation of mTORC1. Thus, although upstream activation of mTORC1 differs between PPP2R5D-related disorder genotypes, treatment with rapamycin or a p70S6K inhibitor warrants further investigation as potential therapeutic strategies for patients.
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Affiliation(s)
- Smolen KA
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Papke CM
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - MR Swingle
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Musiyenko A
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Li C
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Camp AD
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Honkanen RE
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Kettenbach AN
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA
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25
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Sitosari H, Morimoto I, Weng Y, Zheng Y, Fukuhara Y, Ikegame M, Okamura H. Inhibition of protein phosphatase 2A by okadaic acid induces translocation of nucleocytoplasmic O-GlcNAc transferase. Biochem Biophys Res Commun 2023; 646:50-55. [PMID: 36706705 DOI: 10.1016/j.bbrc.2023.01.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 01/15/2023]
Abstract
Post-translational modification (PTM) is crucial for many biological events, such as the modulation of bone metabolism. Phosphorylation and O-GlcNAcylation are two examples of PTMs that can occur at the same site in the protein: serine and threonine residues. This phenomenon may cause crosstalk and possible interactions between the molecules involved. Protein phosphatase 2 A (PP2A) is widely expressed throughout the body and plays a major role in dephosphorylation. At the same location where PP2A acts, O-GlcNAc transferase (OGT) can introduce uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) molecules and mediates O-GlcNAc modifications. To examine the effects of PP2A inhibition on OGT localization and expression, osteoblastic MC3T3-E1 cells were treated with Okadaic Acid (OA), a potent PP2A inhibitor. In the control cells, OGT was strictly localized in the nucleus. However, OGT was observed diffusely in the cytoplasm of the OA-treated cells. This change in localization from the nucleus to the cytoplasm resulted from an increase in mitochondrial OGT expression and translocation of the nucleocytoplasmic isoform. Furthermore, knockdown of PP2A catalytic subunit α isoform (PP2A Cα) significantly affected OGT expression (p < 0.05), and there was a correlation between PP2A Cα and OGT expression (r = 0.93). These results suggested a possible interaction between PP2A and OGT, which strengthens the notion of an interaction between phosphorylation and O-GlcNAcylation.
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Affiliation(s)
- Heriati Sitosari
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan; Department of Oral Biology, Faculty of Dentistry, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| | - Ikkei Morimoto
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Yao Weng
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan; Department of Oral Rehabilitation and Implantology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Yilin Zheng
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Yoko Fukuhara
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Mika Ikegame
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan
| | - Hirohiko Okamura
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 770-8525, Japan.
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Saini LK, Bheri M, Pandey GK. Protein phosphatases and their targets: Comprehending the interactions in plant signaling pathways. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 134:307-370. [PMID: 36858740 DOI: 10.1016/bs.apcsb.2022.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Protein phosphorylation is a vital reversible post-translational modification. This process is established by two classes of enzymes: protein kinases and protein phosphatases. Protein kinases phosphorylate proteins while protein phosphatases dephosphorylate phosphorylated proteins, thus, functioning as 'critical regulators' in signaling pathways. The eukaryotic protein phosphatases are classified as phosphoprotein phosphatases (PPP), metallo-dependent protein phosphatases (PPM), protein tyrosine (Tyr) phosphatases (PTP), and aspartate (Asp)-dependent phosphatases. The PPP and PPM families are serine (Ser)/threonine (Thr) specific phosphatases (STPs) that dephosphorylate Ser and Thr residues. The PTP family dephosphorylates Tyr residues while dual-specificity phosphatases (DsPTPs/DSPs) dephosphorylate Ser, Thr, and Tyr residues. The composition of these enzymes as well as their substrate specificity are important determinants of their functional significance in a number of cellular processes and stress responses. Their role in animal systems is well-understood and characterized. The functional characterization of protein phosphatases has been extensively covered in plants, although the comprehension of their mechanistic basis is an ongoing pursuit. The nature of their interactions with other key players in the signaling process is vital to our understanding. The substrates or targets determine their potential as well as magnitude of the impact they have on signaling pathways. In this article, we exclusively overview the various substrates of protein phosphatases in plant signaling pathways, which are a critical determinant of the outcome of various developmental and stress stimuli.
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Affiliation(s)
- Lokesh K Saini
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Malathi Bheri
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India.
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Sabath K, Jonas S. Take a break: Transcription regulation and RNA processing by the Integrator complex. Curr Opin Struct Biol 2022; 77:102443. [PMID: 36088798 DOI: 10.1016/j.sbi.2022.102443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 07/16/2022] [Accepted: 07/19/2022] [Indexed: 12/14/2022]
Abstract
The metazoan-specific Integrator complex is a >1.5 MDa machinery that interacts with RNA polymerase II (RNAP2) to attenuate coding gene transcription by early termination close to transcription start sites. Using a highly related mechanism, Integrator also performs the initial 3'-end processing step for many non-coding RNAs. Its transcription regulation functions are essential for cell differentiation and response to external stimuli. Recent studies revealed that the complex incorporates phosphatase PP2A to counteract phosphorylation reactions that are required for transcription elongation. Structures of Integrator bound to RNAP2 explain the basis for its recruitment to promoter proximal RNAP2 by recognition of its paused state. Furthermore, several studies indicate that Integrator's cleavage activity is regulated at multiple levels through activators, modifications, and small molecules.
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Affiliation(s)
- Kevin Sabath
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Switzerland
| | - Stefanie Jonas
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Switzerland.
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Verbinnen I, Procknow SS, Lenaerts L, Reynhout S, Mehregan A, Ulens C, Janssens V, King KA. Clinical and molecular characteristics of a novel rare de novo variant in PPP2CA in a patient with a developmental disorder, autism, and epilepsy. Front Cell Dev Biol 2022; 10:1059938. [DOI: 10.3389/fcell.2022.1059938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 11/08/2022] [Indexed: 12/03/2022] Open
Abstract
PP2A-related (neuro) developmental disorders are a family of genetic diseases caused by a heterozygous alteration in one of several genes encoding a subunit of type 2A protein phosphatases. Reported affected genes, so far, are PPP2R5D, encoding the PP2A regulatory B56δ subunit; PPP2R1A, encoding the scaffolding Aα subunit; and PPP2CA, encoding the catalytic Cα subunit—in that order of frequency. Patients with a pathogenic de novo mutation in one of these genes, in part, present with overlapping features, such as generalized hypotonia, intellectual and developmental delay, facial dysmorphologies, seizures, and autistic features, and, in part, with opposite features, e.g., smaller versus larger head sizes or normal versus absent corpus callosum. Molecular variant characterization has been consistent so far with loss-of-function or dominant-negative disease mechanisms for all three affected genes. Here, we present a case report of another PPP2CA-affected individual with a novel de novo missense variant, resulting in a one-amino acid substitution in the Cα subunit: p.Cys196Arg. Biochemical characterization of the variant revealed its pathogenicity, as it appeared severely catalytically impaired, showed mildly affected A subunit binding, and moderately decreased binding to B/B55, B”/PR72, and all B56 subunits, except B56γ1. Carboxy-terminal methylation appeared unaffected, as was binding to B”’/STRN3—all being consistent with a partial loss of function. Clinically, the girl presented with mild-to-moderate developmental delay, a full-scale IQ of 83, mild dysmorphic facial features, tonic–clonic seizures, and autistic behaviors. Brain MRI appeared normal. We conclude that this individual falls within the milder end of the clinical and molecular spectrum of previously reported PPP2CA cases.
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Vaneynde P, Verbinnen I, Janssens V. The role of serine/threonine phosphatases in human development: Evidence from congenital disorders. Front Cell Dev Biol 2022; 10:1030119. [PMID: 36313552 PMCID: PMC9608770 DOI: 10.3389/fcell.2022.1030119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 09/27/2022] [Indexed: 11/23/2022] Open
Abstract
Reversible protein phosphorylation is a fundamental regulation mechanism in eukaryotic cell and organismal physiology, and in human health and disease. Until recently, and unlike protein kinases, mutations in serine/threonine protein phosphatases (PSP) had not been commonly associated with disorders of human development. Here, we have summarized the current knowledge on congenital diseases caused by mutations, inherited or de novo, in one of 38 human PSP genes, encoding a monomeric phosphatase or a catalytic subunit of a multimeric phosphatase. In addition, we highlight similar pathogenic mutations in genes encoding a specific regulatory subunit of a multimeric PSP. Overall, we describe 19 affected genes, and find that most pathogenic variants are loss-of-function, with just a few examples of gain-of-function alterations. Moreover, despite their widespread tissue expression, the large majority of congenital PSP disorders are characterised by brain-specific abnormalities, suggesting a generalized, major role for PSPs in brain development and function. However, even if the pathogenic mechanisms are relatively well understood for a small number of PSP disorders, this knowledge is still incomplete for most of them, and the further identification of downstream targets and effectors of the affected PSPs is eagerly awaited through studies in appropriate in vitro and in vivo disease models. Such lacking studies could elucidate the exact mechanisms through which these diseases act, and possibly open up new therapeutic avenues.
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Affiliation(s)
- Pieter Vaneynde
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, University of Leuven (KU Leuven), Leuven, Belgium
- Leuven Brain Institute (LBI), Leuven, Belgium
| | - Iris Verbinnen
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, University of Leuven (KU Leuven), Leuven, Belgium
- Leuven Brain Institute (LBI), Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, University of Leuven (KU Leuven), Leuven, Belgium
- Leuven Brain Institute (LBI), Leuven, Belgium
- *Correspondence: Veerle Janssens,
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Oyama N, Vaneynde P, Reynhout S, Pao EM, Timms A, Fan X, Foss K, Derua R, Janssens V, Chung W, Mirzaa GM. Clinical, neuroimaging and molecular characteristics of PPP2R5D-related neurodevelopmental disorders: an expanded series with functional characterisation and genotype-phenotype analysis. J Med Genet 2022; 60:511-522. [PMID: 36216457 DOI: 10.1136/jmg-2022-108713] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/11/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND Variants in PPP2R5D, affecting the regulatory B56δ subunit of protein phosphatase 2A (PP2A), have been identified in individuals with neurodevelopmental abnormalities. However, the molecular and clinical spectra remain incompletely understood. METHODS Individuals with PPP2R5D variants were enrolled through Simons Variation in Individuals Project/Simons Searchlight. Data were collected from medical history interviews, medical record review, online validated instruments and neuroimaging review. Genetic variants were biochemically characterised. RESULTS We studied 76 individuals with PPP2R5D variants, including 68 with pathogenic de novo variants, four with a variant of uncertain significance (VUS) and four siblings with a novel dominantly inherited pathogenic variant. Among 13 pathogenic variants, eight were novel and two (p.Glu198Lys and p.Glu200Lys) were highly recurrent. Functional analysis revealed impaired PP2A A/C-subunit binding, decreased short linear interaction motif-dependent substrate binding or both-with the most severe phenotypes associated with variants that completely retained one of these binding characteristics and lost the other-further supporting a dominant-negative disease mechanism. p.Glu198Lys showed the highest C-binding defect and a more severe clinical phenotype. The inherited p.Glu197Gly variant had a mild substrate binding defect, and three of four VUS had no biochemical impact. Common clinical phenotypes were language, intellectual or learning disabilities (80.6%), hypotonia (75.0%), macrocephaly (66.7%), seizures (45.8%) and autism spectrum disorder (26.4%). The mean composite Vineland score was 59.8, and most participants were in the 'moderate to low' and 'low' adaptive levels in all domains. CONCLUSION Our study delineates the most common features of PPP2R5D-related neurodevelopmental disorders, expands the clinical and molecular spectrum and identifies genotype-phenotype correlations.
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Affiliation(s)
- Nora Oyama
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Pieter Vaneynde
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, University of Leuven (KU Leuven), Leuven, Belgium.,KU Leuven Brain Institute (LBI), Leuven, Belgium
| | - Sara Reynhout
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, University of Leuven (KU Leuven), Leuven, Belgium.,KU Leuven Brain Institute (LBI), Leuven, Belgium
| | - Emily M Pao
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Andrew Timms
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Xiao Fan
- Department of Pediatrics, Columbia University, New York City, New York, USA
| | - Kimberly Foss
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rita Derua
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, University of Leuven (KU Leuven), Leuven, Belgium.,SyBioMa, University of Leuven (KU Leuven), Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation and Proteomics, Department of Cellular and Molecular Medicine, University of Leuven (KU Leuven), Leuven, Belgium.,KU Leuven Brain Institute (LBI), Leuven, Belgium
| | - Wendy Chung
- Department of Pediatrics, Columbia University, New York City, New York, USA.,Department of Medicine, Columbia University, New York City, New York, USA
| | - Ghayda M Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA .,Department of Pediatrics, University of Washington, Seattle, Washington, USA
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Kokot T, Köhn M. Emerging insights into serine/threonine-specific phosphoprotein phosphatase function and selectivity. J Cell Sci 2022; 135:277104. [DOI: 10.1242/jcs.259618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
ABSTRACT
Protein phosphorylation on serine and threonine residues is a widely distributed post-translational modification on proteins that acts to regulate their function. Phosphoprotein phosphatases (PPPs) contribute significantly to a plethora of cellular functions through the accurate dephosphorylation of phosphorylated residues. Most PPPs accomplish their purpose through the formation of complex holoenzymes composed of a catalytic subunit with various regulatory subunits. PPP holoenzymes then bind and dephosphorylate substrates in a highly specific manner. Despite the high prevalence of PPPs and their important role for cellular function, their mechanisms of action in the cell are still not well understood. Nevertheless, substantial experimental advancements in (phospho-)proteomics, structural and computational biology have contributed significantly to a better understanding of PPP biology in recent years. This Review focuses on recent approaches and provides an overview of substantial new insights into the complex mechanism of PPP holoenzyme regulation and substrate selectivity.
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Affiliation(s)
- Thomas Kokot
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
| | - Maja Köhn
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
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Zhu X, Ni P, Sturrock M, Wang Y, Ding J, Chang Y, Hu J, Bao Z. Fine-mapping and association analysis of candidate genes for papilla number in sea cucumber, Apostichopus japonicus. MARINE LIFE SCIENCE & TECHNOLOGY 2022; 4:343-355. [PMID: 37073167 PMCID: PMC10077181 DOI: 10.1007/s42995-022-00139-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 06/03/2022] [Indexed: 05/03/2023]
Abstract
The papilla number is one of the most economically important traits of sea cucumber in the China marketing trade. However, the genetic basis for papilla number diversity in holothurians is still scarce. In the present study, we conducted genome-wide association studies (GWAS) for the trait papilla number of sea cucumbers utilizing a set of 400,186 high-quality SNPs derived from 200 sea cucumbers. Two significant trait-associated SNPs that passed Bonferroni correction (P < 1.25E-7) were located in the intergenic region near PATS1 and the genic region of EIF4G, which were reported to play a pivotal role in cell growth and proliferation. The fine-mapping regions around the top two lead SNPs provided precise causative loci/genes related to papilla formation and cellular activity, including PPP2R3C, GBP1, and BCAS3. Potential SNPs with P < 1E-4 were acquired for the following GO and KEGG enrichment analysis. Moreover, the two lead SNPs were verified in another population of sea cucumber, and the expressive detection of three potential candidate genes PATS1, PPP2R3C, and EIF4G that near or cover the two lead SNPs was conducted in papilla tissue of TG (Top papilla number group) and BG (Bottom papilla number group) by qRT-PCR. We found the significantly higher expression profile of PATS1 (3.34-fold), PPP2R3C (4.90-fold), and EIF4G (4.23-fold) in TG, implying their potential function in papilla polymorphism. The present results provide valuable information to decipher the phenotype differences of the papilla trait and will provide a scientific basis for selective breeding in sea cucumbers. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-022-00139-w.
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Affiliation(s)
- Xinghai Zhu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
| | - Ping Ni
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
| | - Marc Sturrock
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, D02 YN77 Ireland
| | - Yangfan Wang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
| | - Jun Ding
- College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023 China
| | - Yaqing Chang
- College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023 China
| | - Jingjie Hu
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic Institution, Ocean University of China, Sanya, 572000 China
| | - Zhenmin Bao
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
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Anwar MI, Li N, Zhou Q, Chen M, Hu C, Wu T, Chen H, Li YP, Zhou Y. PPP2R5D promotes hepatitis C virus infection by binding to viral NS5B and enhancing viral RNA replication. Virol J 2022; 19:118. [PMID: 35836293 PMCID: PMC9284890 DOI: 10.1186/s12985-022-01848-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 06/24/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hepatitis C virus (HCV) infection increased the risk of hepatocellular carcinoma. Identification of host factors required for HCV infection will help to unveil the HCV pathogenesis. Adaptive mutations that enable the replication of HCV infectious clones could provide hints that the mutation-carrying viral protein may specifically interact with some cellular factors essential for the HCV life cycle. Previously, we identified D559G mutation in HCV NS5B (RNA dependent RNA polymerase) important for replication of different genotype clones. Here, we searched for the factors that potentially interacted with NS5B and investigated its roles in HCV infection. METHODS Wild-type-NS5B and D559G-NS5B of HCV genotype 2a clone, J6cc, were ectopically expressed in hepatoma Huh7.5 cells, and NS5B-binding proteins were pulled down and identified by mass spectrometry. The necessity and mode of action of the selected cellular protein for HCV infection were explored by experiments including gene knockout or knockdown, complementation, co-immunoprecipitation (Co-IP), colocalization, virus infection and replication, and enzymatic activity, etc. RESULTS: Mass spectrometry identified a number of cellular proteins, of which protein phosphatase 2 regulatory subunit B'delta (PPP2R5D, the PP2A regulatory B subunit) was one of D559G-NS5B-pulled down proteins and selected for further investigation. Co-IP confirmed that PPP2R5D specifically interacted with HCV NS5B but not HCV Core and NS3 proteins, and D559G slightly enhanced the interaction. NS5B also colocalized with PPP2R5D in the endoplasmic reticulum. Knockdown and knockout of PPP2R5D decreased and abrogated HCV infection in Huh7.5 cells, respectively, while transient and stable expression of PPP2R5D in PPP2R5D-knockout cells restored HCV infection to a level close to that in wild-type Huh7.5 cells. Replicon assay revealed that PPP2R5D promoted HCV replication, but the phosphatase activity and catalytic subunit of PP2A were not affected by NS5B. CONCLUSIONS PPP2R5D interactes with HCV NS5B and is required for HCV infection in cultured hepatoma cells through facilitating HCV replication.
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Affiliation(s)
- Muhammad Ikram Anwar
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology and Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Institute of Human Virology, Zhongshan School of Medicine, and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Ni Li
- Institute of Human Virology, Zhongshan School of Medicine, and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Qing Zhou
- Institute of Human Virology, Zhongshan School of Medicine, and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Mingxiao Chen
- Institute of Human Virology, Zhongshan School of Medicine, and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Chengguang Hu
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology and Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Tao Wu
- Department of Infectious Diseases, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Haihang Chen
- Institute of Human Virology, Zhongshan School of Medicine, and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Yi-Ping Li
- Institute of Human Virology, Zhongshan School of Medicine, and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, China. .,Department of Infectious Diseases, The Fifth Hospital of Sun Yat-Sen University, Zhuhai, China.
| | - Yuanping Zhou
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology and Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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Pan J, Zhou L, Zhang C, Xu Q, Sun Y. Targeting protein phosphatases for the treatment of inflammation-related diseases: From signaling to therapy. Signal Transduct Target Ther 2022; 7:177. [PMID: 35665742 PMCID: PMC9166240 DOI: 10.1038/s41392-022-01038-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/28/2022] [Accepted: 05/25/2022] [Indexed: 11/09/2022] Open
Abstract
Inflammation is the common pathological basis of autoimmune diseases, metabolic diseases, malignant tumors, and other major chronic diseases. Inflammation plays an important role in tissue homeostasis. On one hand, inflammation can sense changes in the tissue environment, induce imbalance of tissue homeostasis, and cause tissue damage. On the other hand, inflammation can also initiate tissue damage repair and maintain normal tissue function by resolving injury and restoring homeostasis. These opposing functions emphasize the significance of accurate regulation of inflammatory homeostasis to ameliorate inflammation-related diseases. Potential mechanisms involve protein phosphorylation modifications by kinases and phosphatases, which have a crucial role in inflammatory homeostasis. The mechanisms by which many kinases resolve inflammation have been well reviewed, whereas a systematic summary of the functions of protein phosphatases in regulating inflammatory homeostasis is lacking. The molecular knowledge of protein phosphatases, and especially the unique biochemical traits of each family member, will be of critical importance for developing drugs that target phosphatases. Here, we provide a comprehensive summary of the structure, the "double-edged sword" function, and the extensive signaling pathways of all protein phosphatases in inflammation-related diseases, as well as their potential inhibitors or activators that can be used in therapeutic interventions in preclinical or clinical trials. We provide an integrated perspective on the current understanding of all the protein phosphatases associated with inflammation-related diseases, with the aim of facilitating the development of drugs that target protein phosphatases for the treatment of inflammation-related diseases.
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Affiliation(s)
- Jie Pan
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center (ChemBIC), Department of Biotechnology and Pharmaceutical Sciences, School of Life Science, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China
| | - Lisha Zhou
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center (ChemBIC), Department of Biotechnology and Pharmaceutical Sciences, School of Life Science, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China
| | - Chenyang Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center (ChemBIC), Department of Biotechnology and Pharmaceutical Sciences, School of Life Science, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China
| | - Qiang Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center (ChemBIC), Department of Biotechnology and Pharmaceutical Sciences, School of Life Science, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Yang Sun
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center (ChemBIC), Department of Biotechnology and Pharmaceutical Sciences, School of Life Science, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China.
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China.
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Hsieh CL, Yao Y, Gurevich VV, Chen J. Arrestin Facilitates Rhodopsin Dephosphorylation in Vivo. J Neurosci 2022; 42:3537-3545. [PMID: 35332081 PMCID: PMC9053844 DOI: 10.1523/jneurosci.0141-22.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/08/2022] [Accepted: 03/17/2022] [Indexed: 01/14/2023] Open
Abstract
Deactivation of G-protein-coupled receptors (GPCRs) involves multiple phosphorylations followed by arrestin binding, which uncouples the GPCR from G-protein activation. Some GPCRs, such as rhodopsin, are reused many times. Arrestin dissociation and GPCR dephosphorylation are key steps in the recycling process. In vitro evidence suggests that visual arrestin (ARR1) binding to light-activated, phosphorylated rhodopsin hinders dephosphorylation. Whether ARR1 binding also affects rhodopsin dephosphorylation in vivo is not known. We investigated this using both male and female mice lacking ARR1. Mice were exposed to bright light and placed in darkness for different periods of time, and differently phosphorylated species of rhodopsin were assayed by isoelectric focusing. For WT mice, rhodopsin dephosphorylation was nearly complete by 1 h in darkness. Surprisingly, we observed that, in the Arr1 KO rods, rhodopsin remained phosphorylated even after 3 h. Delayed dephosphorylation in Arr1 KO rods cannot be explained by cell stress induced by persistent signaling, since it is not prevented by the removal of transducin, the visual G-protein, nor can it be explained by downregulation of protein phosphatase 2A, the putative rhodopsin phosphatase. We further show that cone arrestin (ARR4), which binds light-activated, phosphorylated rhodopsin poorly, had little effect in enhancing rhodopsin dephosphorylation, whereas mice expressing binding-competent mutant ARR1-3A showed a similar time course of rhodopsin dephosphorylation as WT. Together, these results reveal a novel role of ARR1 in facilitating rhodopsin dephosphorylation in vivoSIGNIFICANCE STATEMENT G-protein-coupled receptors (GPCRs) are transmembrane proteins used by cells to receive and respond to a broad range of extracellular signals that include neurotransmitters, hormones, odorants, and light (photons). GPCR signaling is terminated by two sequential steps: phosphorylation and arrestin binding. Both steps must be reversed when GPCRs are recycled and reused. Dephosphorylation, which is required for recycling, is an understudied process. Using rhodopsin as a prototypical GPCR, we discovered that arrestin facilitated rhodopsin dephosphorylation in living mice.
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Affiliation(s)
- Chia-Ling Hsieh
- Ziliha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Yun Yao
- Ziliha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - Jeannie Chen
- Ziliha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
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Wang Y, Huang Q, Huang X, Zhao H, Guan B, Ban K, Zhu X, Ma Z, Tang Y, Su Z, Nong Q. Genetic Variant of PP2A Subunit Gene Confers an Increased Risk of Primary Liver Cancer in Chinese. Pharmgenomics Pers Med 2021; 14:1565-1574. [PMID: 34898995 PMCID: PMC8654694 DOI: 10.2147/pgpm.s335555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/10/2021] [Indexed: 12/14/2022] Open
Abstract
Background Protein phosphatase 2A (PP2A, a serine/threonine phosphatase) is frequently inactivated in many types of cancer, including primary liver cancer (PLC). Genetic variations in PP2A subunits have been reported to be associated with the risk of many types of cancer but rarely in PLC. This study aims to assess the association between functional polymorphisms of PP2A subunit genes and the risk of PLC in Chinese. Methods In a case-control study with a total of 541 PLC patients and 547 controls in Guangxi province of Southern China, we genotyped six putatively functional polymorphisms (rs10421191G>A, rs11453459del>insG, rs1560092T>G, rs7840855C>T, rs1255722G>A and rs10151527A>C) of three PP2A subunit genes (PPP2R1A, PPP2R2A and PPP2R5E) using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry platform. Results The rs11453459insG variant genotypes (ins/ins+del/ins) of PPP2R1A were found to be significantly associated with an increased risk of PLC compared with the del/del genotype (adjusted OR = 1.290, 95% CI = 1.009–1.650), and the number of insert G allele worked in a dose-dependent manner (Ptrend= 0.007). The stratified analysis showed that the effects of rs11453459insG variant genotypes were more evident in the subgroup who drink pond-ditch water (adjusted OR = 3.051, 95% CI = 1.264–7.364) than those never drink (P = 0.041). The carriers of rs11453459 del/ins genotype had a significantly lower level of PPP2R1A mRNA expression in liver cancer tissues than those of the del/del genotype (P = 0.021). Furthermore, we used microcystin-LR, a carcinogen presents in the pond-ditch water, to treat human peripheral blood mononuclear cells and found that the cells from carriers of rs11453459insG variant genotypes induced more DNA oxidative damages than those from the del/del genotype carriers (P < 0.001). Conclusion These findings suggest that the PPP2R1A rs11453459del>insG polymorphism is associated with an increased risk of PLC, especially for persons with a history of drinking pond-ditch water. This insertion/deletion polymorphism may be a susceptible biomarker for PLC in Chinese.
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Affiliation(s)
- Youxin Wang
- Department of Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Qiuyue Huang
- Department of Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Xinglei Huang
- Department of Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Huiliu Zhao
- Department of Clinical Laboratory, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Bin Guan
- Department of Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Kechen Ban
- Department of Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, 77030, USA
| | - Xuefeng Zhu
- Department of Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Zhixing Ma
- Department of Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Yanmei Tang
- Department of Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Zhaohui Su
- Department of Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Qingqing Nong
- Department of Environmental Health, School of Public Health, Guangxi Medical University, Nanning, 530021, People's Republic of China
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